Test tube rack



FIG. 1 is a modified perspective view of a test tube rack showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a left side elevational view thereof;

FIG. 8 is a right side elevational view of an alternate embodiment of my new design, showing a single side support between the top and intermediate tiers of the test tube rack, all other sides being the same as those shown in FIGS. 1-5; and,

FIG. 9 is a right side elevational view of an alternate embodiment of my new design, showing a tab suspended in the space between the two side supports illustrated in FIG. 6, all other sides being the same as those shown in FIGS. 1-5. 

The ornamental design for a test tube rack, as shown and described. 